While both altitude sickness and COVID-19 are associated with breathing difficulties, they are caused by different factors. Altitude sickness occurs due to a drop in air pressure and lower oxygen levels at higher elevations as the body adjusts to a new environment. An invasive coronavirus causes COVID-19, impairing breathing to a sometimes severe extent, and provoking additional symptoms including fever, chills, muscle pain, coughing, sore throat and a loss of senses of smell and taste.